Just as Solomon Richards is about to finish Meltdown, Weston wants to pull the plug on the film, stating that he can get a massive insurance payout; however, Michael does not want to see his first legitimate work destroyed, so he chases after Molly, who has possession of the physical print, before she leaves Los Santos. Michael recovers the film; however, Molly is accidentally killed when she runs in front of an active jet turbine while running away from him, and Solomon reveals they had multiple digital backup copies. During the premiere of Michael's movie, Weston tells Michael that he sent Merryweather mercenaries to assassinate his family at the De Santa house. Michael goes to his house to save his wife and daughter and holds off the assault of Weston's henchmen.

Towards the end of the game, Weston shows up at Franklin's house, telling him that he wants Michael assassinated for ruining several of his business ventures and for getting Franklin involved with the federal government. Franklin tells Weston that he has yet to be paid for his previous work and that Agents Haines and Norton already want him to assassinate Trevor; however, Weston claims that he has the clout to end the careers of both FIB agents. Should Franklin decide to defy both Haines' and Weston's orders, the three team up to track down Weston, kill his personal army, and Weston is forced into the trunk of his car and pushed to the bottom of the ocean. After Weston's death, Merryweather founder Don Percival buys out most, if not all, of Weston's shares in the company, becoming the new majority shareholder in the process.

Trivia

He describes himself as both "Darwinist" and "spiritual".

When he visits Franklin to introduce the game's final mission, he claims that "even the president lets (me) finger his wife".

His black Tornado, the one that is used to kill him in Deathwish, has a vanity plate that reads "MONIED".